Conventional earpiece auditory devices (e.g., earphones, headphones, headsets, monitors, IFB devices, hearing aids, earplugs, etc.) generally include some form of an ear tip or ear mold (used interchangeably herein) to provide for stability and user comfort of a device which is placed in the ear. However, coupling sound from a receiver or speaker into an individual's ear canal presents many design challenges including achieving high fidelity sounds, comfortable fit, acoustic sealing, safety and ease of insertion and removal.
Part of these challenges arise due to the anatomy of the ear canal, which may vary considerably among different users. Typically the ear canal comprises a concha portion which can be thought of as the outer bowl of the ear located behind the tragus. Moving inward, an ear has a transition zone, and an aperture which typically marks the beginning of the ear canal. An ear canal is generally “S” shaped with a first bend starting near the aperture, and a second bend starting near the cartilaginous-bony portion transition. These locations of these bends may vary among different people as well as the diameter and depth of the ear canal. Additionally, the deformations that occur in an ear canal due to jaw movements and other normal motion vary greatly among different people.
Each of these anatomical aspects are generally considered when designing any component which resides in the ear canal. Because of the vast variance between users, some auditory devices, typically hearing aids, utilize custom fit molds to secure a speaker in the ear canal. Such custom fit molds are typically expensive and require complicated fitting and manufacturing processes.
Other solutions include placing generically shaped ear tips over the speaker. Some embodiments of such ear tips are designed to be placed in an ear canal of a user include a soft material which is shaped in a umbrella or mushroom-style fashion, and are designed to circumscribe a speaker assembly. This layout, however, can be less than ideal. For example, because the mushroom portion of the ear tip and speaker assembly are substantially located within the same axial plane, the ability of the ear tip to bend and flex while being inserted is significantly limited by the structure of the speaker assembly. This problem is exacerbated when the speaker assembly is inserted past one or more bends in the ear canal.
Another difficult issue prevalent in the design of ear tips corresponds to methods of securing the ear tip on the speaker assembly itself. For example, it would be unacceptable to have an auditory device configured to be inserted into the ear canal that includes an ear tip which is prone to disconnecting from the speaker assembly within the ear canal. Accordingly, an ear tip cannot sit too loosely on the speaker assembly. Moreover, an ear tip must be generally designed and connected in a manner which prevents forces due to insertion and removal of the speaker assembly itself to allow the ear tip to be separated from the speaker assembly. Because of this, ear tip designers generally may require a portion of the ear tip to have an elastic fit that forms snugly over the speaker assembly. In this manner, the ear tip is not exposed to the normal friction and bending stemming from daily use without the speaker assembly structure acting as a limit on such forces to prevent disconnection of the ear tip from the speaker assembly.
Conversely, an ear tip with such a snug elastic fit maintains an exceedingly tight fit on the speaker assembly and may be difficult for a user to exchange in the event that the ear tip becomes clogged with debris or worn out. This is particularly true in the hearing aid industry where primary users are often elderly patients. Currently, the hearing aid industry typically errs on the side of caution and utilizes ear tips which fit snugly and are exchanged by a specialist.
In non-hearing aid devices, such as audio headphones, typically ear tips do not extend into the ear canal much past the aperture, and certainly not deeply in the ear canal (e.g. near the second bend). In fact, such devices generally seat in the concha of the ear. More recent headphone models may include a tip that seats in the aperture of the ear, while the coupling of the speaker to the ear tip resides outside of the ear. However, for a high number of users, these devices are uncomfortable and cause soreness in the outer ear with prolonged use and are difficult to keep in position properly in the ear.